Plug insert



FIG. 1 is a perspective view of a plug insert showing our new invention;

FIG. 2 is a first side elevation view thereof;

FIG. 3 is a second side elevation view thereof;

FIG. 4 is a third side elevation view thereof;

FIG. 5 is a fourth side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

In the drawings, the broken lines represent unclaimed environment only and form no part of the claimed design. 

CLAIM The ornamental design for a plug insert, as shown and described. 